The radius of a potassium atom is 231 pm. How many potassium atoms would have to be laid side by side to span a distance of 4.77 mm?

To determine the number of potassium laid side by side by a given distance, we simply divide the total distance to the diameter of each atom. The diameter is twice the radius of the atom. We calculate as follows:

number of atoms = 4770 / 231x10^-12 = 2.06x10^13 atoms